The present invention relates to a rearview mirror for vehicles constructed for efficient and optimal assembly, including components shaped for efficient and low-scrap molding and manufacture, components having features integrated into them to reduce the overall number of parts, pieces, and total weight, and components arranged to facilitate mechanical assembly and physical layout as well as electrical interconnection and repair of electrical circuits.
Modern vehicle mirrors often include numerous electrical components that must be powered and also controlled. For example, the electrical components of one proposed high-end exterior mirror will include an electrochromic image-darkening mirror subassembly and control circuit, a heater, a turn signal, and a powered angular adjustment mechanism. Other mirrors, such as interior mirrors, include a multitude of sensors, buttons, and readouts/displays. Routing of wires to support the various electrical components can be a logistic nightmare, and further, even if routed carefully and consistently, can take up considerable space. Also, most mirror designs provide electrical connectors so that the mirror can be electrically coupled to a vehicle's electrical system on or about the same time as the mirror is mechanically attached to the vehicle. It is desirable to reduce the amount of time that it takes to arrange wiring and connectors on the mirror, and to reduce the amount of time it takes to manipulate connectors and then electrically connect the multiple electrical components of a mirror to each other and to the vehicle electrical system.
Another problem caused by multiple components in a mirror is that the mirror becomes thicker in order to make room for the wiring and connectors and also heavier due to the connectors, wires, and related support structure. Modern vehicles place a high emphasis on low weight and small size, especially for non-visible components. Weight, even in small amounts, is an issue in electrochromic mirror subassemblies because these mirrors use a pair of glass elements with an electrochromic layer therebetween. They also require the supporting circuitry and hardware. Glass has a relatively high specific gravity, and since electrochromic mirror subassemblies require a pair of glass elements, these mirror subassemblies tend to be heavier than non-electrochromic mirrors. In opposition to the issue of reducing weight by reducing glass thickness, glass elements must be thick enough to prevent distortion of reflected images, since this is related to a vehicle driver's ability to see around and safely drive a vehicle. Most existing mirror glass elements in EC mirror subassemblies are about 2.2-mm in thickness or greater. Vehicle manufacturers have hesitated going below this thickness because the glass elements will bend too easily, resulting in distortion of the reflected images. Further, a way is needed to support the glass elements in a non-stressed manner, especially during wide temperature fluctuations and other stress-rising incidents that occur in the environment of a vehicle in service.
Further, it is preferable that various functions and features be well integrated into the components of a mirror assembly to minimize the total number of parts and pieces. At the same time, it is often desirable to maintain repairability so that expensive components do not have to be scrapped and thrown away when a defect occurs in other components during the last few steps of a manufacturing process for the mirror. There is tension between the concept of “integrated features and components” and “repairability” when trying to optimize a mirror for manufacture. For example, “well integrated features and components” tend to require less electrical connectors and less manual assembly (i.e. since the components are integrated into the mirror), and initially cost less as a result. However, sometimes it is desirable to add electrical connectors so that defective components can be removed and replaced and so that scrap can be better controlled and/or so that assembly efficiency can be improved.
Recently, some manufacturers are considering placing a turn signal in an exterior vehicle mirror. This can cause several difficulties and complications in a mirror. For example, the light-generating turn signal device adds weight and takes up space, such that the resulting assembly is potentially heavier and larger than mirror assemblies not having this feature. Further, the turn signal device requires additional wiring within the mirror assembly, which can cause assembly concerns related to electrical connections and positioning of connectors, as discussed above. Further, a defective turn signal device non-removably attached to an electrochromic mirror subassembly can result in scrapping out and throwing away a “good” electrochromic mirror subassembly, which is a relatively expensive portion of the overall assembly at that same point in time. At the same time, it is desirable to securely attach the turn signal device to the mirror assembly so that it does not come loose while in service. One reason is because, if the turn signal device came loose in an exterior mirror assembly, dirt and light-blocking matter would soon cover the turn signal device, rendering it ineffective. Also, it could rattle and cause other problems.
It is desirable to improve assembly of the electrochromic mirror subassembly to the angular adjustment mechanism (often called a “power pack”). Historically, the power pack includes an electrically-powered angularly-adjustable mount, and the electrochromic mirror subassembly includes a carrier with a connector having resilient fingers shaped to snappingly engage the adjustable mount. However, as the resilient fingers are flexed to engage and then do engage the adjustable mount, the glass-supporting area around the fingers is distorted. This can be a problem since, if the glass is less than about 2.2-mm thick and the carrier thickness is also minimized for reduced weight, the distortion of the glass-supporting area can read through to the glass, causing noticeable and objectionable distortions in the reflected images. Distortion of the glass-supporting area can be reduced by making the fingers flimsier and not as stiff, however this would result in a reduced retention force and less reliable connection of the electrochromic mirror subassembly to the power pack. Distortion of the glass-supporting area can also potentially be reduced by placement of perpendicular reinforcement webs on the carrier. This, however, adds weight and takes up considerable space if the reinforcement webs are made large enough to do an adequate job. Further, testing has shown that it is not a solution to this problem to merely add a few random reinforcement webs, since very minor bending in a direction perpendicular to the glass elements of the mirror subassembly in any localized area can result in objectionable glass distortions, especially with glass elements at or under 1.6-mm thickness. It is important that the insertion force for attaching the carrier to the adjustable mount not be too high of force, that it not be an inconsistent force, and yet that the retention force not permit looseness, sloppiness, poor and inconsistent retention forces.
In addition to the above, it is desirable to design a carrier for the EC mirror subassembly that can be molded with molding dies that are not complicated and that do not include a plurality of movable pulls and slides that are difficult to maintain. Pulls and slides in molding dies are well known, and are often used to mold parts. However, pulls and slides are expensive to build into a die and to maintain, and can result in increased scrap. Further, it is desirable to provide a carrier that provides ease and reliability of assembly, with few parts and pieces, especially having few small parts and pieces such as screws and separate fasteners that must be manipulated and/or connected without stripping.
Accordingly, a mirror assembly is desired solving the aforementioned problems and having the aforementioned advantages.